Hecht



April 30, 1957 F. HECHT REGISTER WHEEL DRIVE Filed Oct. 15. 1953 INVE'NI'OP: FERDINAND HFCHT United States Patent REGISTER WHEEL DRIVE Ferdinand Hecht, Stuttgart, Germany Application October 15, 1953, Serial No. 386,367

Claims priority, application Germany March 10, 1951 6 Claims. (Cl. 235-61,.6)

The present application is a continuation-in-part application of my copending application Serial No. 274,779 for a Calculating Machine filed on March 4, 1952.

The above parent application discloses a register wheel drive according to which the register wheels are nonpositively driven from a drive shaft on which they are rotatably mounted, and in such manner that the register wheels are taken along by the drive shaft for a complete revolution if a control mechanism is in a position corresponding to a zero value. Consequently, a register wheel performs a single complete revolution if no digit between 1 and 9 is introduced so that the same digit is indicated, whereas in the event that a digit between 1 and 9 is introduced by the control mechanism, a locking means blocks movement of the register wheel while the drive shaft continues rotation. After a time period determined by the introduced digit, the register Wheel is released by the locking means, and again driven by the drive shaft. The above described register wheel drive of the parent application has certain disadvantages, inasmuch as the non-positive drive may cause inaccuracies in the transfer of values, and moreover the above described construction requires a complicated tens transfer mechanism since the shifting from 9 to 0 position is relative to the rotating register wheel and not relative with respect to a stationary support.

It is the object of the present invention to improve the register wheel drive of the parent application, and to provide a positive drive for the register wheel.

It is another object of the present invention to positively drive the register wheel through an angle and for a time period corresponding to an introduced value.

It is a further object of the present invention to lock the register wheel when it is not driven.

With these objects in view the present invention mainly consists in a register wheel drive, comprising, in combination, a register wheel, a drive shaft, coupling means including gear means and adapted to be actuated by a control mechanism for connecting the drive shaft with the register Wheel for a time period corresponding to an introduced digit, the coupling means being movable between a coupling position in which the drive shaft is positively connected to the register wheel for driving the same, and a releasing position, locking means movable between a locking position locking the register wheel against rotation, and a releasing position, and means connecting the locking means with the coupling means and moving the locking means to the locking position whenever the coupling means move to the releasing position.

The arrangement according to the present invention not only improves the reliable operation of the machine, but also permits provision of a simplified tens transfer device. The invention will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing in which:

Fig. 1 illustrates an embodiment of the present invention; and

Fig. 2 illustrates another preferred embodiment of the present invention.

Referring now to the drawings, and more particularly to Fig. 1, the coupling lever 1 is actuated and operated by the control mechanism of the calculating machine in such manner as to be shifted in the direction of the arrow at the beginning of the time period corresponding to the introduced value. Thereby one of the coupling members 3, which pass through slots in the register wheel 4, is shifted from an outer releasing position, to an inner coupling position in which the respective coupling memher 3 projects into a recess in the toothed coupling wheel 6 which is fixedly secured to the drive shaft 5 so that the register wheel 4 is rotated. A locking wheel 7 is fixedly connected to the register wheel 4, and as soon as the drive shaft 5 is positively coupled by the coupling member 3 to the register wheel 4, the locking wheel 7 is forced to rotate with the register wheel and forces the locking lever 8 out of the recess in the locking wheel in which the end of the locking lever 8 is urged by spring 11. The locking lever 8 and the coupling lever 1 are pivotally mounted on the common shaft 9 and are connected to each other by a lost motion device. In the illustrated embodiment a pin 10 fixed on the coupling lever 1 projects into an elongated slot in the locking lever 8 so that a positive connection between the two levers is estab lished during movement of the lever 1 in one direction. When the coupling lever 1 returns to its inoperative position, the locking lever 8 is positively taken along whereby the end portion of the locking lever 8 engages the looking wheel 7 and locks the register wheel 4 directly after the time period corresponding to the introduced value has elapsed.

in order to prevent that the register wheel 4 is taken along frictionally by the shaft 5 at the start of the coupling stroke of the coupling lever 1, the locking lever 8 is pressed by the spring 11 against the locking wheel 7 until the coupling lever 1 has pressed the coupling memher 3 completely and accurately into the center of a recess of the rotating toothed coupling wheel 6.

While the described embodiment operates reliably, the comparatively large mass of the register wheel causes noises and wearing ofi of the parts even if very light materials are used. The disadvantages of the embodiment shown in Fig. l are avoided in the preferred embodiment of Fig. 2. The locking lever 101 is controlled by the control mechanism of the calculating machine in such manner that it carries out a pivotal movement in the direction of the arrow at the beginning of the time period corresponding to the respective introduced values. In this position the locking lever 101 releases the gear 103 which is fixedly connected to the register wheel 192, and simultaneously engages the coupling member 104 by a linkage such as the projecting member 105 which is secured to one end of the locking lever lill. Coupling gear 106 is rotatably mounted on one end of the coupling member 1B4, and is driven from the shaft 109 by a first gear 108 through the intermediate gear Hi7. The direction of rotation of the gear means 196, 107, 108 is changed in accordance with the computing operation which is being carried out so that the register wheel 1&2 rotates in opposite directions during an addition and subtraction, respectively. At the end of the coupling movement of the levers 101 and 194 in the direction of the arrow, the register wheel 102 and the second gear 163 connected thereto are completely released from the locking means and are connected through the gear means 106, 107 with the first gear 108 on the totalizer shaft 9 until the time period corresponding to the introduced value has elapsed, and the locking lever 101, which is operated from the control mechanism of the machine, is actuated to perform a pivotal movement in a direction opposite to the direction indicated by the arrow, so as to move to a locking position in which the register wheel is locked. The coupling lever 104 which is urged by the spring Ht) into an inoperative position, moves in the direction opposite to the direction of the arrow imme diately after the locking movement of the locking lever 101 is terminated. Also, the coupling gear 106 has teeth which are shaped in such. manner as to be forced out of the locked gear 103 whereby the coupling lever is urged into inoperative position.

It will be understood that each of the elements do scribed above, or two or more together, may also find a useful application in other types of calculating machines differing from the type described above.

While the invention has been illustrated and described as embodied in a register wheel drive, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be secured by Letters Patent is:

1. in a caiculating machine, register wheel drive comprising, in combination, a register wheel; a drive shaft; coupling means adapted to be actuated by a control mechanism for connecting said drive shaft with said register wheel for a time period corresponding to an introduced digit, said coupling means including a mu pling member pivotally mounted on said drive shaft for movement between an inoperative position and a coupling position and adapted to be shifted by the control mechanism to one of said positions thereof, means ur ing said coupling member into the other of said positions thereof, gear means rotatably mounted on said coupling member, means for driving said gear means from said drive shaft, and a gear fixedly connected to said register wheel for rotation therewith and meshing with said gear means when said coupling member is in said coupling position; locking means movable between a locking position for locking said register wheel against rotation, and a releasing position; and means connecting said locking means with said coupling means so that the locking means move to said locking position whenever said coupling means move to said releasing position.

2. A register wheel drive as claimed in claim 1 wherein said coupling means include a toothed wheel fixed on said drive shaft.

3. A register wheel drive as claimed in claim 1 wherein said locking means include a locking lever movable between a locking position engaging said gear and blocking movement of the same and of said register wheel, and a releasing position, said coupling member being connected to said locking lever.

4. In a calculating machine, a register wheel drive, comprising, in combination, a register wheel; a drive shaft; coupling means adapted to be actuated by a control mechanism for connecting said drive shaft with said register wheel for a time period corresponding to an introduced digit, said coupling means including a first gear fixed on said drive shaft, a coupling lever pivotally mounted on said drive shaft for movement between an inoperative position and a coupling position, means urging said coupling lever into said inoperative position, gear means rotatably mounted on said coupling lever and meshing with said first gear in any position of said coupling lever, and a second gear fixedly connected to said register wheel for rotation therewith and meshing with said gear means when said coupling lever is in said coupling position; locking means movable between a locking position for locking said register wheel against rotation and a releasing position; and linkage means con necting said locking means with said coupling means and moving the locking means to said locking position when said coupling lever moves to said inoperative position.

5. A register wheel drive as claimed in claim 4 wherein said locking means include a locking lever movable between a locking position engaging said second gear and blocking movement of the same and of said register wheel, and a releasing position; and wherein said linkage means is a projecting member fixedly secured to said locking lever and being engaged by said coupling lever during movement of the same to said inoperative position for moving said locking lever into said locking position.

6. A register wheel drive as claimed in claim 4 wherein said gear means include a coupling gear meshing with said second gear when said coupling lever is in said coupling position; and an intermediate gear meshing with said coupling gear and with said first gear.

References Cited in the file of this patent UNITED STATES PATENTS 

